Yarn feeding mechanisms for flat bed knitting machines



1968 R. c. TAYLOR ET AL 3,396,558

YARN FEEDING MECHANISMS FOR FLAT BED KNITTING MACHINES Filed Nov. 9,1965 11 Sheets-Sheet 1 QQ 1 1 1 4| 0. EV M Q T fimdmmmdmmmdmmwmw w o an!:7 IL i i 1 1 mm .n. v FM v NW 1 mill @W i S g 9 m 4 g L n b QN co mm m.8 2 Mw B \.m mm vmi i m .& .2 m mm 3 mm lo G G3 NwS mm q 9 5 mm mm .3cm Wm m a a a a a a g w i Q a w m a: w w 42 A? a .i i m YARN FEEDINGMECHANISMS FOR FLAT BED KNITTING MACHINES Filed NOV. 9, 1965 1963 R. c.TAYLOR ET AL 11 Sheets-Sheet 2 YARN FEEDING MECHANISMS FOR FLAT BEDKNITTING MACHINES Filed Nov. 9, 1965 3, 1968 at. TAYLOR ET AL 11Sheets-Sheet 3 mNT Aug. 13, 1968 R. c. TAYLOR ET AL YARN FEEDINGMECHANISMS FOR FLAT BED KNITTING MACHINES Filed NOV. 9, 1965 llSheets-Sheet 4 E m, m

I/O. 8 52 2 N m mm |E i AKHJMR 3R m: Q R aw {My 0 b w Hr o .NN. N9 v R Iw 4 0 .S ,wR 0 Q a o Q mm 0 Q mm ma? 0 E E R A H Q E u m Q (ri Q Q:-@.----\o @S S Q: 3 E m? YARN FEEDING MECHANISMS FOR FLAT BED KNITTINGMACHINES I Filed Nov. 9, 1965 R c. TAYLOR ET AL Aug. 13, 1968 11Sheets-She et 5 aw N NE m y A r/ o 2 Q i QM M Gd. mm 9 m: 0 o mm m Z I 2mm 2 m2 Aug. 13, 1968 R. c. TAYLOR ET AL 3,396,558

YARN FEEDING MECHANISMS FOR FLAT BED KNITTING MACHINES Filed Nov. 9,1965 11 Sheets-Sheet. 6

Aug. 13, 1968 R. c. TAYLOR ET AL r. 3,396,558

YARN- FEEDING MECHANISMS FOR FLAT BED KNITTING MACHINES Filed Nov. 9,1965 11 Sheets-Sheet 7 Nm 3 E u: m2

JJNJA Aug. 13, 1968 R. c. TAYLOR ET AL 3,396,553

YARN FEEDING MECHANISMS FOR FLAT BED KNITTING MACHINES 11 Sheets-Sheet 8Filed Nov.

1 Hm mw Qm M ww mm mm Qwm E s- 3, 1968 R. c. TAYLOR ET AL 3,396,558

YARN FEEDING MECHANISMS FOR FLAT BEI) KNITTING MACHINES Filed Nov. 9,1965 ll Sheets-Sheet 9 Aug. 13, 1968 R. C. TAYLOR ET AL YARN FEEDINGMECHANISMS FOR FLAT BED KNITTING MACHINES 11 Sheets-Sheet 10 Filed Nov.9, 1965 1968 R. c. TAYLOR ETAL 3,396,558

YARN FEEDING MECHANISMS FOR FLAT BED KNITTING MACHINES Filed Nov. 9,1965 ll Sheets-Sheet 11 United States Patent 3,396,558 YARN FEEDINGMECHANISMS FOR FLAT BED KNITTING MACHINES Robert Cecil Taylor, Blaby,and Anthony S. Brittain,

Borbage, England, assignors to Ratby Engineering Company Limited, EarlShilton, Leicestershire, England Filed Nov. 9, 1965, Ser. No. 507,071Claims priority, application Great Britain, Nov. 12, 1964, 46,069/64 19Claims. (Cl. 66-132) ABSTRACT OF THE DISCLOSURE Flat bed knittingmachine having two pairs of nip rollers for positively feeding yarn toneedles during to and fro traverses of the cam carriage in respectivelyopposite directions. An endless chain passed around sprockets andconnected with the cam carriage, is provided for driving at least onenip roller of each pair through the medium of one of the chain sprocketsand an associated gear train; the machine includes means for separatingthe nip rollers of each pair at required times and permitting them tomove into cooperative relationship at other times. The gear trainincludes a change-gear for controlling stitch and course length.

This invention appertains to yarn feeding or furnishing mechanisms forapplication to new or existing flat bed knitting machines.

So far as the present invention is concerned, a flat bed knittingmachine means one comprising at least one fiat or straight horizontalneedle bed or plate equipped with a straight series of independentlyoperable needles, and wherein a yarn, under appropriate tension, is fedto and taken by the needles by which it is weft knitted into fabric, thesaid yarn being drawn from a supply by joint longitudinal traverses inopposite directions of a thread carrier and a cam carriage, and by theknitting action of knitting cams or a lock mounted on this carriage.Practical forms of such a flat bed knitting machine are usually providedwith two opposed flat or straight horizontal needle beds or plates whichare set either at an angle of 90 to each other, as in a V- bed machineof the Lamb type, or in a common horizontal plane as in a purl stitch orlinks and links type of machine. In a Vbed machine each of the twoneedle beds or plates may be equipped with a separate series ofindividually operable needles, whilst in a flat machine of the purlstitch or links and links type there is only one set of such needleswhich are selectively transferable from one bed or plate to the otherthrough the medium of needleactuating jacks, all as is well known tothose acquainted with the art.

The invention, moreover, is applicable both to singlelock and todouble-lock fiat bed knitting machines. A single-lock machine has oneset or pair of locks (one lock or cam system to each needle bed orplate) whereas in a double-lock machine two sets or pairs of locks aremounted on the same traversible carriage and are set as closely togetheras possible. A double-lock machine puts on two courses of knitted loopswith each traverse of the carriage across the machine, as against onecourse with the single-lock machine.

The invention is especially concerned with positive yarn feedingmechanism for determining and controlling stitch and course length andconsequently also fabric or garment length.

Thus, the primary object of the present invention is to provide, in orfor a flat bed knitting machine, means whereby the amount of yarnknitted per stitch and hence per course is maintained substantiallyconstant, the in- 3,396,558 Patented Aug. 13, 1968 vention accordinglybeing based on the fact that uniformity in stitch length, course lengthand fabric or garment length is dependent on the precise amount of yarnconsumed by the machine.

Now under ordinary working conditions, the variables that tend to causediiferences in coarse length are several: for instance, there are yarnfriction variables, changes in machine running speed, temperaturevariations, variations in the tension and physical properties of theyarn being fed and so on. A particular aim of the invention, thereforeis to provide a positive yarn feeding and controlling mechanism adaptedto obviate these variables and changes by means of nip rollers measuringthe yarn as it goes into the knitting machine and so controlling stitchlength and course length.

In this regard the invention provides improvements in the previouslyproposed arrangement disclosed in the complete specification of UnitedKingdom Letters Patent No. 948,254, wherein there are provided, incombination in a fiat bed knitting machine in which the thread carriertraverse extends to and fro beyond the selvedges of the work, a positiveyarn feeding device comprising nip rollers at least one of which isdriven and the other of which is separable therefrom, means foroperating the said device for positively feeding yarn at predeterminedconstant or ditferent rates dependent upon the machine speed and uponinvariable or dilferent movement relationship respectively between thedevice and the relevant thread carrier, and selvedge control means whichare operable for stopping and re-starting for positive feed of yarn atpredetermined times before the end and after the re-start respectivelyof the thread carrier traverse.

In accordance with the characteristic and distinguishing feature of thepresent invention there are provided, in or for association with a flatneedle bed or plate of a knitting machine, two pairs of positive feednip rollers, one pair being operable to feed a yarn to the needles inthe said bed or plate during each traverse of the cam carriage in onedirection and the other pair being operable to feed the yarn to theseneedles during each carriage traverse in the reverse direction.

These two pairs of nip rollers, in use appropriately spaced apart in thedirection of the length of the needle bed or plate, are for feeding yarnto the independently operating needles actuated by or from theparticular cam system or lock which is related to that bed or plate. Thenip rollers of the pair located nearest the carriage are adapted to beclosed together to form a nip for feeding the yarn when the carriage ismoving away from the rollers, whereas the rollers of the other pairfurthest from the carriage are adapted to be similarly closed togetherto form a nip for feeding the yarn as the carriage returns, i.e. ismoving towards the rollers. Thus, it is convenient to refer to the niprollers nearest the carriage as the going rollers, and the rollersfurthest from the carriage as the coming rollers.

An important point to appreciate at the outset is that there are twopairs of nip rollers, i.e. four rollers, for positively feeding eachyarn which is to pass through a thread carrier and to be taken andknitted by needles in the machine. Consequently, if it is desired toemploy a yarn feeding mechanism constructed, arranged and operableaccording to this invention for positively feeding a single yarn toneedles in one needle bed or plate only of a flat bed knitting machineand if, moreover, only a single cam system or lock on the cam carriageis adopted for operating these needles, then the said yarn feedingmechanism will comprise but a single pair of going and a single pair ofcoming rollers, But if it is the intention to adopt such a yarn feedingmechanism for positively feed ing two single yarns to sets of needles inthe front and the rear needle beds or plates of a flat bed knittingmachine respectively, then in this case, and again assuming that only asingle cam system or lock on the cam carriage is used for operating theneedles in each of the two beds or plates, the mechanism will comprisetwo sets of going and coming nip rollers, viz. a pair of going rollersand a pair of coming rollers for the front bed or plate and a furtherpair of going rollers and a further pair of coming rollers for the rearbed or platethe two sets of nip rollers being located at respectivelyopposite sides of the longitudinal median line of the machine extendingbetween the two parallel beds or plates.

A further possibility is, however, envisaged in regard to a double-lockmachine wherein there are provided on the cam carriage two locks perneedle bed or plate: in such an alternative case, in which two yarns canbe fed via two thread carriers to a set of needles in each of the twoopposed beds or plates, it may be desirable or necessary to provide foursets of nip rollers, one set for feeding each of four yarns. But in thisrather more complicated arrangement, two of the sets of nip rollersrelating to one pair of locks, may be combined into one yarn feedingunit, whilst the remaining two sets of nip rollers relating to the otherpair of locks may for convenience be similarly combined into a secondyarn feeding unit.

For convenience in the following further description most of the latterwill be concentrated on a unitary positive feed mechanism or headapplied to a two-bed flat knitting machine wherein only one carriagelock per bed is provided-or, at least, is in use. It is, however, to beclearly understood that what applies to one unitary mechanism or headapplies equally to any other similar mechanism or head provided in themachine: similarly, what applies to either of two companion sets of niprollers (one set to each of two opposed needle beds) applies equally tothe minimum of one set (two pairs) of nip rollers.

In order that the invention may be more clearly under stood and readilycarried into practical effect, a specific constructional example ofpositive yarn feeding mechanism applied to a two-bed fiat knittingmachine will now be described with reference to the accompanyingdrawings, wherein,

FIGURE 1 is a front view of the said knitting machine showing thepositive yarn feeding mechanism applied thereto, the machine and thesaid mechanism being respectively drawn in light and relatively heavylines,

FIGURE 2 is an end view of the machine as seen in the direction of thearrow A in FIGURE 1,

FIGURE 3 is a front view of the unitary positive feed head located atthe right-hand end of the machine,

FIGURE 4 is a vertical sectional view through the head as seen from thefront of the machine and showing the mechanism lying adjacent to therear cover plate of the casing of the head,

FIGURE 5 is another vertical sectional view through the head as seenfrom the rear of the machine and shows the gearing and mechanism lyingadjacent to the front cover plate of the said casing,

FIGURE 6 is a detail sectional view taken on the line VIVI of FIGURE 4,

FIGURE 7 is a further detail sectional view taken on the line VHVII ofFIGURE 5,

FIGURE 8 is a sectional view taken on the line VIII VIII of FIGURE 5,

FIGURE 9 is a plan view, partly in section, of the rear part of thepositive feed head, showing inter alia, the upper rollers of the twopairs of nip rollers for positively feeding a yarn to needles in therear needle bed of the knitting machine,

FIGURE 10 is a similar plan view, also partly in section, of the frontpart of the said head including two pairs of nip rollers for feeding ayarn to needles in the front needle bed of the machine,

FIGURE 11 is a fragmentary front view of a portion of a cross beam orrail constituting a chain guide included in the mechanism, and showsmounted on this beam or rail various actuating and control devices, aswill be hereinafter described,

FIGURE 12 is a plan view of all that is shown in FIG- URE 11,

' FIGURE 13 is a cross-sectional view taken on the line XIII-XIII ofFIGURE 11,

FIGURE 14 is a cross-section taken on the line XIV- XIV of FIGURE 13,

FIGURE 15 is a detail rear view of the beam or rail, as seen in thedirection of the arrow A in FIGURE 12, illustrating means for connectingthe cam carriage of the knitting machine with the chain guided in saidbeam or rail,

FIGURE 16 is a plan view depicting a mounting assembly for the tail endof the cross beam or rail and also an associated tensioner for the chainguided therein,

FIGURE 17 is a vertical sectional view of the same, and

FIGURE 18 is a diagram illustrating the electrical control circuitry ofthe positive yarn feeding mechanism.

Like parts are designated by similar reference characters throughout thedrawings.

Referring to FIGURES 1 and 2, the letters KM designate atypical two-bedflat knitting machine. The front needle bed or plate of this machine isindicated at 1 and the rear needle bed or plate at 2. The longitudinallytraversible cam carriage is represented at 3. The numeral 4 indicates afew typical thread guides for feeding yarns to the needles in the needlebeds or plates. At the left-hand side of 1 there is shown, in purelydiagrammatic fashion, a jacquard selecting mechanism 5, whereas at 6 inFIGURE 2 there is represented an electric motor for driving the machine.

At the right-hand end of the machine frame F viewing the machine fromthe front, there is attached a mounting bracket 7 upon the top of whichis supported the casing C of a stationary positive feed head. Thiscasing comprises a rectangular framework including a closed bottom 8 anda mainly closed top 9, there being secured to this framework a frontcover plate 10, a rear cover plate 11, and an end plate 12 disposed atthe left hand end of the casing C. The opposite end of the latter (shownat the right-hand side of FIGURE 4 and the left-hand side of FIGURE 5)is left entirely open. The casing C is divided longitudinally into twohalves along a line 13 (FIGURE 9 and 10) coincident with a medial planeextending be tween the two parallel needle beds or plates 1 and 2. Uponthe top 9 of the casing C there are provided two suitably spacedbrackets 14 between the left-hand ends of which is secured one end of across beam or rail 15. As shown in FIGURE 2 this beam or rail extendshorizontally the full length of the machine and, at its tail end remote'from the casing C, is secured in a mounting unit 16 in turn supportedupon a bracket 17 bolted to the left-hand end of the machine.

Extending laterally right through the upper part of the casing C are twoparallel spaced d-riveable shafts, viz. a going shaft 18 and a comingshaft 19. Upon the outer ends of these shafts are rigidly secured uppersteel rollers 20 each of which is adapted for cooperation with a lowerpressure roller 21 or wheel. The pressure rollers 21, which arerubber-covered and free-running, are mounted upon spindles 22 set in aso-called D-arm such as that indicated at 23 in FIGURE 6. The niprollers 20 and 21 of each pair are superimposed, the lower roller 21being movable upwards to close the nip and downwards to open the nip.But whilst in the illustrated example only one of each pair of niprollers is adapted to be positively driven, it is to be clearlyunderstood that, if desired, both rollers of each pair could be driven.

The going and coming shafts 18 and 19 carrying the upper steel rollers20 are arranged to be continuously driven from an endless chain 24, e.g.of the roller type, through the medium of a train of gears 25, 26, 27,28, 29, '30 and 31 (see FIGURES 3, 5 and 7), the chain in turn beingdriven by the cam carriage 3 as it traverses to and fro, i.e.alternately from left to right and right to left. The upper and lowerruns of the chain 24 are guided within longitudinal channels and 151)formed in the cross beam or rail 15 (see FIGURES 11, 12 and 14). Thesaid chain, moreover, is passed around two chain sprockets 32 and 33(see FIGURES l6 and 17). The spindle 34 upon which the sprocket 32 issecured is rotatably mounted in :a ball bearing 35 provided within theappropriate one of the brackets 14. The gear 25 (meshing with the gear26) is secured upon the end of the rotary spindle 34 remote from thechain sprocket 32.

The chain sprocket 33, on the other hand, is secured upon a spindle 36which, as shown in FIGURES 16 and 17, is mounted to rotate freely withinbearing holes formed in the parallel limbs 37a of a forked component 37housed within the tail mounting unit 16. The opposite ends of thespindle 36 are located in horizontal slots 16a formed in the spacedvertical Walls of the unit 16. The forked component 37 is connected witha chain-tensioning device T which comprises a stem 38 screwed at itsinner end into the rear of the said component, an adjusting screw 39adjustable in the rear extremity of the tail mounting unit 16 and anintermediate tension spring 40 connecting the two. A suitablyspring-influenced detent 41, pivotally mounted upon the stem 38 andarranged to co-operate with a toothed rack 42, constitutes a non-returnratchet device adapted to retain the stem 38 and hence also the forkedcomponent 37 in any position to which it may be drawn to the left (seeFIGURE 17) by appropriate manipulation of the screw 39 when tensioningthe endless chain 24. A plate 43 longitudinally grooved at 43:: on itsunderside and secured upon the top of the unit 16 provides an abutmentfor the detent 41. Bolts for securing the tail end of the cross beam orrail 15 in the mounting unit are indicated at 44.

The end portions of the going and coming shafts 18 and 19 are mounted inball bearings 45 which are set in the front and rear cover plates 10 and11. The bearings 45 set in the front cover plate 16 are shown in FIGURE7, it being understood that the rear cover plate 11 is omitted from thisfigure merely for simplicity in illustration. Thus, the illustratedpositive feed head comprises two sets of nip rollers so that there aresecured upon the going shaft 18 (the left-hand shaft as viewed from thefront of the machine) at least two driveable steel going rollers 2(l-oneat the front and the other at the back of the aforementioned median line13, whilst upon the coming shaft 19 (i.e., the right-hand shaft) thereare similarly secured at least two coming rollersagain one at the frontand the other at the back of the casing C. Preferably, however, and asshown in the drawings, there are provided on each of the opposite endsof each of the two shafts 18 and 19, a plurality of steel rollers 20 ofrespectively different diameters for selective co-operation with thecompanion lower presser roller 21. Thus, two or even three diiferentsized rollers 20 may he slipped onto and rigidly secured to an endportion of either the going or the coming shaft, according torequirements, and as more clearly shown in FIGURES 7, 9 and 10. Eachsteel roller 20 slipped onto either of these two shafts is indirectlykeyed to the latter by an axially extending locating pin 46 and isclamped in position by a knurled nut 47 applied to a screwthreaded outerextremity of the relevant shaft. If, say, it is desired to fit only twosteel rollers 20 onto an end portion of either of the going or comingshafts, then a space reserved for a third steel roller may betemporarily occupied by a spacer 48 of the same thickness.Alternatively, a plurality of initially separate and individuallyremovable upper nip rollers such as 20 for fitting onto one end ofeither the going or the coming shaft may be replaced by a single uppernip roller having a stepped form and being of such axial extent as toprovide adjoining portions having annular surfaces of respectivelydifferent diameters enabling a plurality of yarns to be guided beneaththe said adjoining portions. In either case, by arranging for the freerunning lower pressure rollers 21 to be selectively moved laterally todifferent extents inwards and outwards, by means hereinafter to bedescribed, it is possible to nip and positively feed a selected one ofthe said plurality of yarns in the production of patterning or otherspecial effects, Yarn guides such as those indicated at 49 in FIGURE 3are mounted on the front and the rear cover plates of the casing C toguide yarns beneath the upper steel rollers 20 or the adjoining rollerportions of the various diameters.

Stitch length and hence also course length may be controlled by rollersize or/and by the selected size of a change gear included in theaforementioned train of gears. For example, in the illustrated train ofgears provided within the casing C, the spur gear 25 may be the changegear. Thus, whilst a wide range of stitch lengths can be achieved bychanging the sizes of the positively driven rollers 20, nevertheless forcertain ranges of stitch length it is necessary to change the gear 25for one of a different diameter. But, whenever the gear 25 is changed,it is necessary to roll the gear 26 around the gear 27 immediately belowit whilst maintaining 26 and 27 in mesh; this is to enable the gear 26to be bodily swung in either direction both to facilitate actualchanging of the gear 25 and also to enable the gear 26 to be disposed inmesh with the changed gear. For this purpose, the gear 26 is mounted onan arm 50 which at its lower end is bossed at 51 and arranged to pivotfreely about a lay shaft 52 carrying the combined or connected gears 27and 28 (see FIGURE 7). The arm 50 is secured in position by a nut andbolt 53, 54, the bolt extending through an arcuate slot 53 formed in apart such as 56 of or on the casing C. The gear 29 is carried by afurther lay shaft 57, extending parallel with the shafts 18, 19 and 52.The going and coming shafts 18 and 19 have rigidly secured thereto thegears 30 and 31 respectively. The arrangement of the gear train isaccordingly such that whenever the chain sprocket 32 is driven in theclockwise direction, as viewed in FIGURE 5, the going shaft 18 willrotate clockwise and the coming shaft 19 anti-clockwise, and vice versa.The upper part of the change gear 25 is protected by a cover 58 securedupon the top 9 of the casing C.

For transmitting the motion of the cam carriage 3 to the endless chain24, and thence driving the chain sprocket 22 alternately in oppositedirections, the lower run of the said chain is coupled to a pick-upelement 59 in the form of an arm which is adjustably mounted upon asupport 60. This support is welded upon the top of a depending verticalpeg 61 which is slidable heightwise within a bush 62 (see FIGURE 14).The latter is secured by a set screw 63 within a bossed portion 64a of abracket 64 adapted to be bolted to the longitudinally traversible camcarriage 3 of the machine. The driving of the two shafts 18 and 19 inthe manner described thus maintain a constant relationship between therectilinear speed of the cam carriage and the rotational speeds of thesaid driven shafts.

Now in all cases more yarn must be positively fed when the carriage ismoving away from the unitary mechanism or head than when it isapproaching the latter. The course length in the fabric or garment,however, will usually, but not necessarily always, be the same inwhichever direction the carriage is travelling. This result may beachieved by a judicious dimensioning of the gears in the aforesaid trainwhich permits of the commensurate driven shaft rotating at a higherspeed than the other in a fixed relationship. The driven shafts 18 and19 have secured thereon nip rollers 20 of different diameters so thatthe combination of different rotational speeds and different rollerdiameters provides for commensurately different rates of yarnfeedresulting in a comparatively high rate of feed when the traverse ofthe carriage 3 is going away from the nip rollers 20 and 21 and acomparatively low rate of feed when the carriage traverse is comingtowards the said rollers.

To facilitate the production of special rib and like effects such, forexample, as Milano rib, in a case where the unitary positive feedmechanism or head comprises two sets of nip rollers, one to each of twoopposed cam systems or locks, the two driven shafts 18 and 19 may, ifdesired, each be transversely split into two so that in addition to theprovision of different speeds going and coming as aforesaid, the drivenrollers at the front and the rear of the mechanism or head can be causedto rotate at respectively different speeds determined by separate changegears of respectively different diameters.

Separation of the going and coming nip rollers 20 and 21 mayconveniently be effected by associated spring-infiuenced mechanicalmembers (hereinafter to be .described) arranged to be actuated byelectric solenoid and switch means, the switch means being located nearthe selvedge needles and operable by a part moving with the cam carriageof the flat bed knitting machine, and selector means operable in reversesenses at respectively opposite extremities of the carriage strokesbeing provided to permit closure of the nip or nips of only the pair orpairs of rollers appropriate to the direction of carriage travel takingplace at any one time and to simultaneously maintain in a positivemanner separation of the remaining pair or pairs of nip rollers.

Thus, in the illustrated arrangement of the last described feature,applied to a head equipped with two sets of nip rollers, two solenoidsare employed-one SOL. 1 in respect of the pairs of going and coming niprollers at the front of the casing C and the other SOL. 2 in respect ofthe similar pairs of nip rollers at the back of the said casing. Thisenables the said pairs of nip rollers at the front end back to be openedand closed entirely separately and in such a way as to accord with themovements of the two thread carriers 4 functioning in conjunction withthe front and rear needle beds or plates 1 and 2 respectively. In thisconnection it has to be borne in mind that throughout each carriertraverse in either direction the front thread carrier usually leadswhilst the rear thread carrier trails, this circumstance dictating thenecessity for the opening and closing of the two pairs of front niprollers a little in advance of the similar pairs of rear nip rollers.Two pairs of micro-switches MS. 1 and MS. 2 and MS. 3 and MS. 4 aremounted in sequence on the longitudinal cross beam or rail 15. Thesemicroswitches, moreover, are operable by pairs of rocker members 65 and65 and 65 and 65 disposed for accurate control of the pairs of going andcoming nip rollers 20, 21 in relation to the fabric selvedges. That isto say, one pair of rockers 65 and 65 is located near to the casing Cand the other pair 65 and 65 remotely therefrom. The bracket 64 on thecarriage 3 is fitted with a striker 66 for operating the rockers. Eachrocker is fitted at its ends with adjustable rollers 67 and 68 arrangedto be respectively acted upon by the oppositely sloping edges 66a and66b of the striker 66. Assuming that the knitting machine is beingviewed from the front, the pairs of nip rollers being, as shown, mountedat the right-hand end of the machine, then during the first phase of theoutward traverse of the carriage 3 away from the rollers, i.e. fromright to left, the striker 66 first passes the right-hand rollers 67 ofthe near pair of rocker members 65 and 65 and then its edge 66b strikesthe left-hand rollers 68 to operate, one after the other, the two nearswitches MS. 1 and MS. 2, as the result of which the front and rearsolenoids SOL. 1 and SOL. 2 are energized to permit closing first of thepair of going rollers associated with the front bed or plate 1, and thenof the pair of going rollers associated with the rear bed or plate 2.During the final phase of the said outwards traverse of the carriage 3,(just about to commence in FIGURE 1) the striker 66 first passes therollers 67 of the remote pair of rocker members 65 and 65 and strikesthe rollers 68 thereon to operate, one after the other, the two remoteswitches MS. '3 and MS. 4 in such a way as to deenergize the twosolenoids SOL. 1 and SOL. 2 similarly one after the other, to effectfirst opening of the closed nip of the pair of going rollers associatedwith the front needle bed or plate 1 and then with a slight delay, theopening of the closed nip of the pair of going rollers associated withthe rear needle bed or plate 2. Conversely, during the first phase ofthe inwards traverse of the carriage towards the casing C and therollers, i.e. from left to right, the striker 66 first passes theleft-hand rollers 68 of the said remote pair of rocker members 65 and 65and thereupon strikes, with its inclined edge 66a, the right-handrollers 67 thereof to reversely operate seriatim the said two remoteswitches MS. 4 and MS. 3 as the result of which first one and then theother of the two solenoids SOL. 2 and SOL. 1 are energized to permitclosure first of the pair of coming rollers associated with the rearneedle bed or plate 2 and then of the pair of coming rollers associatedwith the front bed or plate 1. Then, during the final phase of theinwards traverse of the carriage the striker 66 first passes theleft-hand rollers 68 of the near pair of rocker members 65 and 65 andstrikes the right-hand rollers 67 thereof to operate one after the otherthe two near switches MS. 2 and MS. 1 which again de-energize the twosolenoids SOL. 2 and SOL. 1 similarly one after the other, to causefirst opening of the nip of the pair of coming rollers associated withthe rear needle bed or plate 2 and thereafter the opening of the nip ofthe pair of coming rollers associated with the front bed or plate 1.

The description of FIGURE 18, which, illustrating the electric controlcircuitry, shows in purely diagrammatic fashion, the solenoids SOL. 1and SOL. 2 and the two pairs of micro-switches MS. 1 and MS. 2 and MS. 3and MS. 4, will be completed later when all of the switches in thecircuitry have been mentioned. In the meantime it will be convenient todescribe the manner in which the free-running, rubber-covered pressureroller: 21 at the front and the back of the casing C are carried, andthe means by which these rollers are pressed down to separate them fromthe upper steel rollers to open the nips of the pairs of rollers and arereleased and permitted to rise into contact with the said upper steelrollers to close the nips of the pairs of rollers at required times.

Thus, the two pressure rollers 21 at the front (and also at the back) ofthe casing C are, as previously mentioned, mounted upon spindles 22 setin arms 23. As seen in FIG- URE 6, the bossed inner ends of these arms23 are rigidly secured upon the outer ends of short shafts 69 mounted toturn in bushes 70 secured in the relevant (front or rear) cover plate ofthe casing C. To the inner reduced ends 69a of the shafts 69 are rigidlysecured bell-cranks 71. Upon the arm 71a of each of the two bell-cranksis mounted a roller 72 whilst the outer ends of the other arm 71b ofeach bell-crank is of hooked form and has anchored thereto a controllingtension spring 73. The ends of the springs 73 remote from thebell-cranks 71 are anchored to the bottom 8 of the casing C.

Mounted within the casing C immediately above the rollers 72 on eachpair of hell crank arms 71a is a longitudinally shiftable selector bar74 having a cut out 74a in the edge thereof opposing the said rollers.The two selector bars 74 are transversely connected to operate in unisonand are arranged to be shifted back and forth by a common centrallypivoted lever 75 the upper extremity of which is slotted at 75a toengage a pin 76 fixed in a small bracket attached to the appropriateside of a longitudinally movable racking bar 78.

This racking bar is supported from the cross beam or rail 15 through themedium of screws 84 screwed into the said beam or rail and extendingthrough slots 78a formed in the said bar (see FIGURE 14 and 15). Spacerssuch as are mounted on the screw 83 and located between the heads of thescrews and the back of the cross beam or rail. The racking bar 78 isthus shiftable to and fro, i.e. rightwards and leftwards, by meanspresently to be described. But to exercise control over these to and fromovements and prevent bouncing of the racking bar 78, the latter isarranged to slide through tension devices such at that indicated at 79in FIGURES 11 and 12. Each of such devices comprises friction blocks 80and 81 held together frictionally by the pressure exerted thereon by acompression spring 82 associated with a screw 83 which latter extendsthrough a slot 78b in the racking bar and is screwed into the cross beamor rail 15. The racking bar 78, moreover, has secured to itlongitudinally spaced operating blocks 86 each carrying on the topthereof a cam-following roller 87. The rollers on these operating blocksare arranged to be acted upon by the operative edges 88a of cams 88which are pivotally mounted at 89 upon brackets 90 bolted upon the crossbeam or rail 15. The pivoted cams 88 are controlled by springs 91arranged as shown in FIGURES 1, 11 and 12. The pivoted earns 88 areformed with profiled noses 88b in turn arranged to be acted upon by acam-striking roller 92 which is carried by an upstanding stem 93 securedin a portion 64b of the aforementioned bracket 64 bolted to the camcarriage 3 (FIG- URE As the cam-striking roller 92 contacts theoperative edge 88a of the relevant pivoted cam 88 during a traverse ofthe carriage 3 in either direction, the said roller enters an open-endedguide slot 94a formed in a fixed steady plate 94 disposed immediatelyabove the cam. Each of these plates 94 is slotted at 94b to avoidfouling the nuts 95 employed to retain in position the cam-followingrollers 87.

The form of the cut out 74a in the appropriate edge of each of the twoconnected selector bars 74 is such as to provide at opposite ends ofeach such bar, on its lower edge, oppositely inclined cam edges 74b and74c for action upon the rollers 72. But also for action upon the tworollers 72, both at the front and also at the back of the casing C, toassist in the control of the relevant bellcranks 71 and hence also thecorresponding pressure rollers 21, there are provided two associatedpivoted levers 96 and 97. The lever 96 which fulcrums about a stud 98secured in the relevant cover plate of the casing C and extends througha slot 74d in the relevant selector bar 74, is formed with three limbs96a, 96b and 960. Of these three limbs, 96a is connected by means of astraight link 99 with the relevant solenoid SOL. 1 or SOL. 2 dependingon whether the linkage is at the front or back of the casing C. The limb96b carries a roller 100- and is formed with a lower straight edge 96dopposing the relevant roller 72. The limb 960 is connected to one end ofan adjustable tension spring 101 the opposite end of which is anchoredin the end plate 12 of the casing. The simple lever 97, on the otherhand, has only one limb in the outer end of which is formed an elongatedhole or slot 97a accommodating the roller 100 on the limb 96b of thelever 96. The lever 97 fulcrums about a stud 102 which is secured in thesame cover plate as the stud 98 and extends through a slot 74a in theappropriate selector bar 74. The lower straight edge 97b of the lever 97opposes a roller 72. Thus, whenever the particular solenoid (SOL. 1 orSOL. 2) connected with the link 99 is energised and consequently pulledin, the said link will be drawn back suchwise as to swing the lever 96about its fulcrum stud 98 against the action of the controlling spring101. As a result the limb 96b will be swung upwards to move the edge 96dwell clear of the roller 72 opposing it. But by virtue of the permanentengagement of the roller 100 within the elongated hole or slot 97a inthe lever 97, the latter will be simultaneously swung up to move theedge 97b similarly well clear of the other roller 72. It will beappreciated that in this way energisation of the solenoid results in therelevant two bellcranks 71 being freed for control by the correspondingselector bar 74. Conversely, whenever the solenoid is deenergised itreleases the link 99 so that the lever 96 is reversely turned under theaction of the spring 101 so that both the lever limb 96b and theassociated lever 97 will be swung down together. As a consequence, theedges 96d and 97b will press down upon the rollers 72, therebydepressing them and the bell cranks 71 into lower positions clear of therevelant selector bar 74 so that the latter can be safely shiftedrightwards or leftwards.

The arrangement is accordingly such that towards the extremity of eachstroke of the cam carriage 3 in the rightward direction the racking bar78 is longitudinally shifted to the right as a consequence of which theconnected selector bars 74 are both shifted to the left through themedium of the centrally pivoted lever 75, Whereas towards the extremityof each leftward carriage stroke the said racking bar is shifted to theleft and the selector bars 74 are shifted to the right. The form of thecut out 74a in the edge of each selector bar 74 opposing the rollers 72on the bell cranks 71 connected with the arms 23 carrying the lowerrubber-covered pressure rollers 21 at the elevant side of the positivefeed unit or head allows only the pressure roller appropriate to thedirection of carriage travel to swing up under the action of its spring73 into co-operative nip relation with the companion upper driven roller20 whenever the appropriate solenoid is energised, the other pressureroller 21 at that side being positively held down against its springaction by the inclined edge 74b or 74c of the selector bar edge. Thus,from what has been said and also from the foregoing description of theoperation of the rocker members 65 65 65 and 65 and the microswitchesMS. 1, MS 2, MS. 3 and MS. 4, it will be realised that whenever a switchis operated to de-energise a solenoid only one lower pressure roller 21at the front or the back of the casing C will be pressed down to open anip, the other pressure roller at that side of the mechanism alreadybeing held down by the relevant selector bar 74. Conversely, whenever aswitch is operated to energise a solenoid only one lower pressure roller21 at the side concerned will be free to swing up into co-operative niprelation with its companion upper driven roller 20, the other lowerpressure roller at that side being positively prevented from swinging upby the selector bar 74. But, of course, shifting of the selector barsalternately to the right and to the left at the respectively oppositeextremities of the carriage strokes determines which pairs of niprollers are to be open and which closed at any particular operation oftwo switches one after the other as hereinbefore described. In allinstances, the solenoidoperated spring-controlled levers 96 and 97function to hold the bell c-ranks 71 down during shifting of theselector bars 74 in either direction, and to release the bellcranks forcontrol by the selector bars subsequent to each such shift.

In the principal case of a fiat bed knitting machine having a cam systemor lock and a thread carrier functioning in conjunction with each of twoneedle beds or plates, one thread carrier always preceding the other,the complete arrangement may conveniently, and as shown, include achange-over switch COS operation of which, via a relay R3 (FIGURE 18),changes the connections of the solenoids SOL. 1 and SOL. 2 to thevarious microswitches on the beam or rail 15. The changeover switch COS,when provided, may be operated in this sense by or from the racking bar78 as this is longitudinally shifted at the extremity of each outwardtraverse of the machine carriage 3 away from the nip rollers 20, 21.Each time the carriage returns to the rollers and the racking bar 78 isthereby automatically shifted in the opposite direction the change-overswitch COS is released and the solenoidto-switch connections revert totheir initial condition. In each of FIGURES 12 and 16 it will be seenthat there is attached to the tail end of the racking bar 78 a smallblock 103 into which is screwed an adjustable abutment 11 screw 104adapted to operate the change-over switch COS by direct contacttherewith.

If, as already described, each of the two driven going and coming shafts18 and 19 has secured upon each end thereof either a plurality of upperrollers 20, or a stepped upper driven roller, a plurality of yarns to beguided beneath the separate rollers or adjoining portions of a steppedroller, then by arranging for the lower pressure rollers 21 to beselectively moved laterally to different extents inwards and outwards itis possible to nip and positively feed a selected one of the saidplurality of yarns in the production of patterning or other specialeffects. In this specific example illustrated in FIGURES 3-6, the twopairs of lower, free-running pressure rollers 21 respectively at thefront and back of the casing C are slidable along their spindles 22towards and away from one another and are rigidly combined withcircumferentially grooved yokes 105 in which are engaged the outer endsof yarn change plates such as 106, the lower central portions of theseplates being connected through slidable spindles 107 to linkages adaptedto be operated by a pivoted lever 108 (FIGURE controlled by studs or bit109, 110 on an intermittently movable pattern dictating component suchas the chain 111. The spindles 107 are arranged to slide axially throughbosses formed on the inner sides of the casing cover plates and 11. Theinner ends of these spindles are as depicted in FIGURE 6, articulated tooppositely arranged bell crank levers 112 and 113. The ends of the lastmentioned levers remote from the spindles 107 are pivotally connected toa common adjustable link 114 which, through the medium of yet anotherbell crank lever 115 is in turn connected with the lower end of a rod116. This rod extends upwardly and at its upper extremity is pivotallyconnected with the lever 108.

The construction, arrangement and operation of this particular systemare such that if a stud or bit 109 or 110 raises the pivoted lever 108the two pairs of lower pressure rollers 21 will simultaneously belaterally moved inwards towards one another through the connections 107,112, 113, 114, 115 and 116. Conversely, if by a movement of the patterndictating component 111 the pivoted lever 8 is lowered the two pairs ofpressure rollers 21 will be drawn laterally outwards away from oneanother. Studs or bits of varying heights enable the two pairs ofpressure rollers to be selectively moved to various positions forcooperation, when the nips are produced, either with selected uppersteel rollers or selected portions of stepped upper driven rollers forthe purpose of feeding the desired yarns. Although the upper drivenrollers 20 or the adjoining portions of stepped rollers will usually beof different diameters there is no limitation in this respect since allof these rollers or adjoining portions could be of the same orsubstantially the same diameter.

When, as in the illustrated example, a patterning chain 111 is provided,then this is passed over a pattern wheel 117 located near to the pairsof nip rollers, this wheel being provided with a circular series ofratchet pins 118 adapted to be racked round intermittently by a pivotedpawl or clawker 119 upon one end of the racking bar 78. A leaf spring120 controls 119. Thus, when the carriage moves to its extreme positionaway from the rollers 20, 21 the racking bar 78 is longitudinallyshifted as previously described, and this shift is utilised to cause thepawl or clawker 119 to rack round the pattern wheel 117 to the extent ofone step, whereas on return of the carriage towards the rollers theracking bar is reversely shifted and sets itself in readiness for thenext racking or indexing operation. For accurately locating andcentralising the pattern wheel 117 each time it is turned a step by thepawl or clawker 119, there is provided a pivoted centralising lever 121having on its lower edge a downwardly protuberant nose 121a adapted toengage between two of a further circular series of pins 12 122 providedon the side of the pattern wheel remote from the ratchet pins 118 (seeFIGURES 4 and 9). The centralising lever 121 is urged downwardly by acontrolling tension spring 123. For turning the pattern wheel 117 byhand there is provided a knob 124.

Whenever the herein described positive feed mechanism is required to beput out of commission this can be done electrically, at the dictates ofthe pattern chain 111, via a bluff out switch BLO (FIGURES 5 and 18).Appropriate actuation of this switch may serve to isolate from thesolenoids SOL. 1 and SOL. 2 the micro-switches on the cross beam or rail15. As will be seen, the switch BLO is carried by a plate 125 and isarranged to be actuated by contact with the top edge of a lever 126(FIGURE 10) brought about by virtue of the latter being raised by a studor bit on the chain. In this regard it will be noted in FIGURE 10 thatthe links of the chain 111 are formed to provide two parallel tracks inone of which the bits for raising the lever 108 are disposed and in theother of which are disposed other bits for actuating the lever 126.

At its lower end the chain 111 is passed around a sprocket 127 which, asillustrated in FIGURE 8, is mounted for rotation about a spindle 128carried by a block 129. This block is adjustable axially along a supportrod 130 secured at its upper end in a depending portion of a bracket 131on which the pattern wheel 117 and an upper chain sprocket 132 combinedtherewith is rotatably mounted. A set screw 133 turnable by a knob 134is provided to set the block 129 in position after an adjustment to suitthe length of the particular pattern chain being used.

Turning again to FIGURE 18, it will be seen that there are included inthe 24 volt A.C. circuit two relays R1 and R2 associated respectivelywith the two solenoids SOL. 1 and SOL. 2 and each adapted to be closedand opened, by actuation of the relevant micro-switches as hereinbeforedescribed, before the corresponding solenoid can be respectivelyenergised and de-energised by the application thereto and cutting offtherefrom of current from a source of higher voltage, e.g. 240 volts. Tand T are the terminals of the 24 volt A.C. supply. Operation of thechange-over switches COS to move it alternately between contacts C and Ccauses the contactors of the relay R3 to move alternately between thefull-line and dotted-line positions. Whenever the bluff out switch BLOis so actuated as to cause it to open, the microswitches MS. 1, MS. 2,MS. 3 and MS. 4 will be isolated from the solenoids SOL. 1 and SOL. 2.The circuitry includes a 24 volt tell-tale lamp L, a panel switch PSwired into the high voltage side of the system and fuses F and FAlthough the relays R1, R2 and R3 can operate with the switch PS open,the said switch must, of course, be closed before the solenoids willoperate. The following lists show the wired positions of the variousmicro-switches:

Switch Operation Wired position MS. 1 Solenoid operating.-.

. Nonglally closed, held open.

Nonlgially open, held closed.

BLO. I: Normally closed. COS Changeover Normally open.

13 provided with welded-on bits of different heights. The sequence ofbits is predetermined to accord with pattern cards on the knittingmachine.

As an alternative to the adoption of a pattern wheel or its equivalent,a punched tape system with an accompanying reader device may beemployed. From this all the various operations of the feed unit or headcould be controlled, through the medium of either mechanical linkages orelectrical means.

Stop motions, e.g. incorporating two-bar electrode and dropper devices,are preferably provided between the or each positive feed unit and theknitting machine. One such device is indicated at 135 in FIGURE 1.

We claim:

1. In a flat bed knitting machine including, in combination, aframework, a needle bed mounted in said framework, needles in said bed,a longitudinally transversable cam carriage mounted on the framework totravel along a course, first in one direction and then in the reversedirection, said cam carriage having a cam system for operating saidneedles, a thread carrier for supplying yarn to the needles, and aregulating means for maintaining substantially constant the amount ofyarn knitted for each run of the cam carriage along said course, saidregulating means including two pairs of positive feed nip rollers, onepair of feeding yarn to the needles during each traverse of the camcarriage in said one direction, and the other pair for feeding yarn tothese needles during each carriage traverse in the said reversedirection, at least one of the nip rollers of each pair being a driveroller which drives the other roller of its pair from power receivedfrom the feed machine, and means for separating the said rollers of eachpair at required times and for permitting them to move into cooperativerelationship at other times, the improvement wherein said machineincludes an endless chain supported on, and movable about sprocketswhich are rotatably connected to the machine and are drivingly engagedwith said chain, said chain extending the length of the machine andgenerally parallel to the course along which the cam carriage travels,means for positively engaging the cam carriage with said chain such thatthe chain is positively driven to and fro by rectilinear movement ofsaid cam carriage in said one direction and said reverse direction, anda drive means for positively engaging the said chain with said driverollers such that the drive rollers are positively rotated by movementof said chain, whereby a constant relationship is maintained between therectilinear speed of the cam carriage and the rotational speed of thedrive rollers.

2. The invention of claim 1 including a cross beam supported on themachine by brackets at opposite ends of the machine and extending thelength of the machine and generally parallel to the course along whichthe cam carriage travels, said endless chain being mounted on said crossbeam.

3. The invention of claim 1 wherein said drive means comprises a geartrain connecting one of said spockets to said drive rollers.

4. The invention according to claim 1, wherein the means for positivelyengaging the cam carriage with the chain includes a pick-up arm mountedon a support and coupled to a run of the endless chain; a depending pegto which said support is attached, and a bushed bracket in which the pegis slidable vertically, said bracket being bolted to the traversable camcarriage.

5. The invention according to claim 1, wherein the nip rollers of eachpart superimposed, the upper roller being on metal and being the saiddrive roller, and the lower roller having a resilient periphery andbeing movable vertically towards and away from the upper roller.

6. The invention according to claim 1 wherein said drive means includestwo spaced parallel shafts each having rigidly secured thereto one ofthe said drive rollers,

the shafts being connected in said drive means to be rotated in oppositedirections.

7. The invention according to claim 3, wherein the gear train includes achange-gear means for permitting at least partial control of stitchlength and hence also course length.

8. The invention according to claim 1 including a separating meanslocated near the ends of the cam carriage stroke and operable by the camcarriage for simultaneously maintaining separation of both pairs of niprollers, and selector means operable in reverse senses at respectivelyopposite extremities of the carriage strokes for permitting closure ofthe nip of only the pair of rollers appropriate to the direction ofcarriage travel taking place at only one time and when the nip rollersare not acted upon by the said separating means.

9. The invention according to claim 6 wherein each of the two shafts hassecured thereon a plurality of separate upper nip rollers of differentdiameters to enable a plurality of yarns to be guided beneath theseparate rollers, and including means for selectively moving the lowerpressure rollers laterally to different inward and outward positions tonip and feed a selected one of the said plurality of yarns.

10. The invention according to claim 8 wherein said separating meansincludes a pair of solenoids, and a pair of electrical switches foroperating the solenoids, the switches being mounted on a longitudinalcross beam extending the length of the machine and generally parallel tothe course of travel of the cam carriage, said switches being actuatedby movable members disposed on the said beam to control the solenoidsand thereby control engagement of the nip rollers during movement ofsaid cam carriage, and including a striker member mounted on the camcarriage of the machine and movable therewith for operating said movablemembers in response to movement of said cam carriage.

11. The invention according to claim 10 including a pair of bell-cranks,one bell-crank connected to a roller of each pair of rollers, and springmeans urging the bellcranks to engage their associated pair of rollers,and wherein said separating means includes a pair of levers springbiased to cause disengagement of both pairs of nip rollers and includinga link connecting the levers to the armature of one of said solenoids,so that operation of that solenoid by its associated switch moves thelevers so that the bell-cranks are free from operative engagement withsaid nip rollers thereby permitting closure of the pair of rollerspermitted by the selector means.

12. The invention according to claim 11, wherein the selector meansincludes a selector bar arranged to be shifted back and forth by alongitudinally movable racking bar which is mounted on the cross beam tobe shifted to and from by means movable with the cam carriage of themachine.

13. The invention according to claim 12 wherein a longitudinal edge ofthe selector bar is recessed and s0 shaped as to provide spaced andoppositely inclined cam edges for action on the spring-influencedbell-cranks.

14. The invention according to claim 12 wherein the racking bar includesspaced blocks, each carrying a roller, and including cam leverspivotally mounted upon the said crossbeam and arranged to be acted uponand turned by a roller mounted on the cam carriage.

15. The invention of claim 12 including a change-over switch forchanging the connections of the solenoids to the switches on the crossbeam, said change-over switch being a micro-switch arranged to beoperated by the racking bar at the extremity of each outward traverse ofthe machine carriage away from the nip rollers.

16. The invention according to claim 9 wherein the lower pressurerollers are slidable axially along spindles and have circumferentiallygrooved portions in which are engaged the outer ends of yarn changeplates, the latter being mounted on guided shafts movable to differenteX- 15 tents axially by intermediate connections connected with apivoted lever controlled by bits on an intermittently movable patterndictating component.

17. The invention according to claim 16 wherein the pattern dictatingcomponent is a chain passed over a pattern wheel which is provided withratchet means adapted to be racked around intermittently by a pivotedpawl mounted upon the racking bar.

18. The invention according to claim 17 including bits on the chain foraction on a movable member arranged for action, at desired times, upon abluff out switch opperation of which renders the yarn feeding mechanisminoperative.

19. The invention according to claim 12 wherein the selector meansfurther comprises a cam plate mounted on the cross beam adjacent eachspaced block and spring biased away from said spaced block andpositioned to be moved against the spaced block to shift the racking bar16. when acted upon by said roller mounted on the cam carriage.

References Cited UNITED STATES PATENTS 3,026,696 3/1962 Marker 66126 X2,586,205 2/ 1952 Cobert 66126 FOREIGN PATENTS 463,911 4/ 1937 GreatBritain.

948,254 1/ 1964 Great Britain.

871,804 3/ 1953 Germany.

888,915 9/1953 Germany.

363,114 7/1962 Switzerland.

MERVIN STEIN, Primary Examiner.

RONALD FELDBAUM, Assistant Examiner.

